The single particle tracking system

Ai Tang Chang, Yi-Ren Chang, Sien Chi, Long Hsu

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In an optical tweezers system, the force measurement with a resolution less than pico-Newton can be achieved by precise measurement and analysis of the trapped particle trajectory. Typically, this single particle tracking technique is realized by a quadrant position sensor which detects the scattering lights of the trapping laser beam from the trapped particle. However, as the radius of the trapped particle is larger than the wavelength of the trapped laser, the scattering pattern becomes complicated, and it limits the tracking region and the signal sensitivity on the trapped particle. To solve this issue, an extra probing laser with optimized focal offset according to the trapping laser is applied to improve the flexibility and performance of our particle tracking system for each particle size. A rule of thumb between the optimized focal offsets and particle size is also concluded from the experimental results and theoretical simulations.

Original languageEnglish
Title of host publicationOptical Trapping and Optical Micromanipulation VII
DOIs
Publication statusPublished - 2010 Oct 27
EventOptical Trapping and Optical Micromanipulation VII - San Diego, CA, United States
Duration: 2010 Aug 12010 Aug 5

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume7762
ISSN (Print)0277-786X

Other

OtherOptical Trapping and Optical Micromanipulation VII
CountryUnited States
CitySan Diego, CA
Period10/8/110/8/5

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Keywords

  • Particle tracking
  • Photonic force microscopy
  • Quadrant-photo detector

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

Cite this

Chang, A. T., Chang, Y-R., Chi, S., & Hsu, L. (2010). The single particle tracking system. In Optical Trapping and Optical Micromanipulation VII [77622Q] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 7762). https://doi.org/10.1117/12.860934